The recent adoption of proof of stake as a consensus mechanism by the Ethereum blockchain has resulted in almost all of its power consumption being canceled. An event that, inevitably, once again highlighted the energy gobbled up by cryptocurrencies, in particular, the bitcoin that it is said to consume. as much electricity as a country like Iceland. CQFD, a recent study from the University of Cambridge shows that the king of cryptocurrencies is struggling to erase its environmental footprint.
Based on proof-of-work, and thus permanent mining of energy-intensive compute farms, the bitcoin ecosystem has seen in recent years a proliferation of projects aimed at greening it, relying on renewable energy sources or using heat. generated to supply heating networks. , for instance. Except that, according to Cambridge Bitcoin Electricity Consumption Index (CBECI)62% of the digital currency’s energy mix is still made up of fossil fuels, and most mining farms receive electricity from coal or gas-fired power plants.
Less coal, more gas
If we notice a slight improvement – since bitcoin was 65% dependent on fossil fuels last year – it is clear that this progress is too slow to meet the current challenges, in a climate of emergency. . It should be noted that according to this index, bitcoin is less reliant on coal (its level of use has fallen from 47% to 37% in a year), but more reliant on gas (from 16% to 25% in the cryptocurrency energy mix). .
At the same time, the sum of electricity consumed by bitcoin coming from nuclear power plants, hydroelectric facilities or wind and solar farms has gone from 35% to 38% in one year. With drought problems recently affecting the ability to generate electricity using dams, the Cambridge researchers note that hydropower has fallen from 20% to 15% in bitcoin’s energy mix.
Of course, although digital remains a minor point in the need to reduce our dependence on fossil fuels and fight global warming, it is a sector that must also invent new models and do everything possible to minimize its impact, also in increase. . However, cryptocurrencies represent, according to some experts, a third of digital energy consumption. Hence the importance of seeing ecosystems like bitcoin migrate to a cleaner operation.
Difficult data to add
It should be remembered, however, that the cryptocurrency sector is still very poorly regulated and its operation is largely opaque, which makes large-scale data collection very difficult. This is why the University of Cambridge has developed its own index based on the location of the world’s main mining deposits and their main sources of energy. Therefore, we understand that there is a margin of error in the figures given, which perhaps explains why other studies are more favorable to bitcoin, such as the (orientated?) one from the American Bitcoin Mining Council lobby, which estimates that 60 % of bitcoin’s energy mix comes from renewable energies.
“We are trying to show what is the footprint of bitcoin […] Your energy mix really has a big impact on your greenhouse gas emissions.”, summarizes Alexander Neumueller who directs this work in Cambridge. In 2022, bitcoin is expected to generate some 48.4 million tons of CO2 equivalents. This would correspond to a decrease of 14% compared to 2021, explained in large part by the fall in the price of the cryptocurrency, which reduced its interest among miners. However, bitcoin just crossed $20,000 and appears to be rising again.